A lightning-fast laser lightshow could help detect explosive powders from a distance, a study in the August 11 Proceedings of the National Academy of Sciences suggests.

The researchers took advantage of a physical phenomenon known as Raman scattering, in which some of the light shining on a surface interacts with the material’s vibrating molecules before scattering away. The frequency of this scattered light serves as a fingerprint of the material. The researchers found they could use short pulses of green light to distinguish between explosive and inert powders from 400 meters away.